Apparatus for producing frozen confections



April 1956 E. THOMPSON, JR

APPARATUS FOR PRODUCING FROZEN CONFECTIONS 5 Sheets-Sheet 1 Filed Aug.31, 195] A TTORNE Y5.

April 3, 1956 E. THOMPSON, JR 2,740,264

APPARATUS FOR PRODUCING FROZEN CONFECTIONS Filed Aug. 31, 1951 5Sheets-Sheet 2 m m l I [Q 3'3 i Rs 1 I k f. w I I H I I I Q Q I:

1' Mi a; I Q g 1' I I I I I Q i I (I I' a| m I I I 1W I a 1 l .5 J 000 oq 1 III A TTORNE Y5 April 3, 1956 E. THOMPSON, JR

APPARATUS FOR PRODUCING FROZEN CONFECTIONS 5 Sheets-Sheet f5 1 N V ENTOR. 5075'? V 7;omp5o4/ p a/azzmvzw zzw Filed Aug. 31, 195] ATTORNE Y5.

April 1956 E. THOMPSON, JR

APPARATUS FOR PRODUCING FROZEN CONFECTIONS 5 Sheets-Sheet 4 7s INVENTOR.5M5? Y OMA Q Q A TTOR NE Y5 u rdp km Mp mm Filed 51, 1951 April 3, 1956THOMPSON, JR 2,740,264

APPARATUS FOR PRODUCING FROZEN CONFECTIONS Filed Aug. 31, 1951 5Sheets-Sheet 5 IN V EN TOR.

A TTOR NE Y5 United States Patent APPARATUS Fora PRQDUCING ruonnucoNnncrroNs iErnery Thompson, Jr., New Rfiheile, N. Y., assignor to E erhe 'M h h & -.Supp y empauy, New "York, N. Y., a corporation of New YorkApplication August 31, 1951, Serial No. 244,630 8 Claims. ree-a4 Thepresent invention relates to apparatusfor ,rnaking and serving frozenconfection products ,and to operating mechanism and control systemsthereof, such devices, though capable of producing a variety of typesoffrozen products, being most familiar to the public in theproductionand sale of the frozen confection called irozen cus rd A general objectof the present invention is .to provide such apparatus and controlsystem thereof which are easily and simply made in an economical and.rapirl rnan- .ner in mass production, .the parts being readily-assemhlecl withminimum manipulation, the devices efiiciently beingoperable ;i n .an assured and fool-proofmanner to permit the mostunskilled of operators consistently to produce afhigh .quality productwhile avoiding operational shutdown directiyattributable to incantiousmanipulation of controls.

A more specific object of the present invention ,is to provide simplefreezer structure featuring uncomplicated supply of liquid stock andgaseous medium for .efiicient attainment of a desired degree of overrunin .the plastic product and with simple automatic control of thesupp'lies thereof.

Another object of the present invention is the provision ;of;si rnplebut sturdy and effectively operabledasherstruc- .ture which .iseasilyand-economically .made and readily serviced and cleaned.

A further-object of the present .inventionis .to provide a .controlsystem for such .treezer apparatus which is .efiiciently sensitive toreturn conduit temperature so-..as

to assure most efiective ,controlof the ;temperature,of the irozenplastic product in the freezer .withinthe limits of and willin partappear hereinafter.

The {invention accordingly comprises the features pf construction,combination of elements and arrangement of parts, which will beexemplified in .the constructions .hereinaftersetforth, and the scope ofthe invention will he indicatedin the-claims.

For ,a .fuller understanding of the .nature and objects .of theinvention, reference should be had to :the {following detaileddescription taken in connection with .theaccom- ,panyin-g drawings, inwhich:

Fig. 1 is a side elevational view, with parts broken away and insection, and others diagrammaticallys'hown,

,of an embodiment of apparatus of the present ginvention for producing"frozen confections;

Fig. 2 is a from end elevational view of the apparatus shownin Fig. '1;

Fig.8 is a sectional view, to an enlarged scale-"with parts broken awayand in section, taken substantially on line-3 3 ofFig. 1;

Fig. 4 is "an axial section, to an enlarged scale, with parts brokenaway, .of the jacketed cylinder .and an embodiment of the dasherstructure of the apparatus shown nfig. l arrdtaken substantially on line44 of .Fig. 5;

Fig. 5 is a detailed transverse section vtaken substantial- Fig. 6' isan exploded perspective view, with parts hrolgen away and in section, of,a portion of :the .dasher stnucture and the driving means therefor atthe inletend which are sh n in :Ei s .4 an

'Fig. 7 isa yiewsimilar to Big. ,6 .of parts of thepther endte'f t eslashe fi u e 'heyrm is L d 5;

Rig. 8 is aside eles ational view .toa reduced scale of the e ,pe e thde h me e sh w 1 Fi 4 t Hee s isi a en ar e e a l e fla he s met e he rw it 4 te-B i e -i Fie- 0, esplen i e h teed term at s ashe st u tu Fig.11 is an enlarged perpsective detailof thereceiving e n d Io fth dasherstructure embodiment shownin Fig. ,10;

.Fis-

i a s t he v en sub n ial o has 1.271 2 Fi .1 and shewinsin .de e t insth t l ne which it is to'herotated and a whipping ,or rniqiing harwhich may be emp oy d h ewit i F 3 e .eh rse :n a e s d M 9 [Que 9 the eetin en advancing bledesse l e sisshe .stse tur 'emhed me sh w hiss-r 11and 1: 1

i 1 s i e pe i p ede. -.d. e i-with rests in pen of thedifie .e' th ehgee dre hed herst eet reshewn in i es 1 1 1 ends-show n means-fe su erthe ei 15 is ,a diagrammatic ,or schematic -view ,of a eeritrol system.employable to advantage .in .the apparatus gQf his 4 Re r i i he drwing in wh e ik eethe el QQlIfifYJSiW DP U l I D -li, it will be ssen ata p efer ed e eilh e t ar u e a iqhe es Li ez eet en o h p s n eat e mac m ris h su ort n vbase structure 2 e ed h vafeesias o suitab y eh s are e t h rh n evi et 9 2E31 22 on'which other parts -are mounted..iiponthe platt m m 12 issuitehly m n e in eietete ed r-n ze .ably suhstantially horizontal ,position a freezer .23, s by .mea of e b l -124 atem o ar ee-a euros, such as ,by means .of suitable .br t fleet 2, .26and a hee su t ie d sh zdr s hros es, u h e i d yen P l e r ns e u.stye.-i die te Lintlotted linesat'28i n Fig. 1.

.The -freezer :unit ,23 comprises aiaterai ror s ubstantiaiiy hori t lel n t d y in s it h w esed .It inl nd by eed d e -i tle hy ihee :"351-A mi -s i th c lin e '29 i r utreunde b a etfit s ran iae e 2 suit bseve e shy 21 1 1 1 'nsjmeee we hsselplurelityef. a ac leashed. zertnding cork strips which cooperate with underlying-.hands of insulation34 beyond theends of the jacket anden- .gageddirectly about the exposedendsmf the oyllnder w lu j t d s from o p s e d e th iee set i she headh in u a e et ebl e e ef .r ensia d na yre s s i j s rips as r th een eEissaud t. A housing 55' .coversthe cer 1 t ral section of {the ja ketea n u a d l de :2 an e li flriea eeyer 3,6 6 cooperate withend plates37, 37 to cover the insuiation about the protrudingends of the cyiinder.

W thihfi jba ea i i t hlymeunte hehsha sl sherre t meehe m a ef i e a 'iifla sy ysteh t heh m eh nismm eempris aneleet ie ih tor38 supported onhanger structure 3 9 and suitablylhelte d,such as t t-40, to thepulleyidriving structure inhous- -ing -2 7,'as shown in dotted linesinFig.}1.- The refrigerant circulatory .system may comprise a compressor41 conmected *by an outlet conduit diagrammatically shown "at 42 throughcondenser coil 43 to the usual reservoir 44. From the reservoir 44, asupply conduit 45 for compressed refrigerant preferably feeds through adehydrating dryer 46 to jacket inlet or supply duct 47, through asolenoid valve 48 and an expansion valve 49 connected in series. Asshown in Figs. 1 and 4, supply duct 47 communicates at the bottom withheat exchanger space 50 inside jacket 32 within the housing 35. A returnline duct 51 communicates with space 50 at the top, also within thejacket 35, to extend down through a hole in platform top 22 into thebase housing 21 for return connection to compressor 41, as seen in Figs.1 and 4. The compressor 41,

of course, includes suitable motive means, such as a selfcontainedelectrical motor indicated at 52 in Fig. 15.

The means for supplying fluid or liquid stock to cylindrical freezingchamber 53 provided by the interior of the cylinder 29 preferablycomprises an elevated storage supply tank 54 mounted for gravity feedabove the freezer unit 23 and preferably upon the casing 35 thereof bymeans of leg brackets 55, 55, as shown in Figs. 1 and 2. An'eductionpipe 56 connects a low point of the bottom of the interior of the tank54 to the bottom of temporary storage tank 25 so as to feed fluid stockto the latter by force of gravity. The outlet opening of the eductionpipe 56 is circumscribed by a valve seat 57 on which seats afloat-operated lift valve 58, suitably connected by linkage and levermeans 59 to a float 60 located within tank 25 to control the supplythereto of liquid stock and while amounts of the latter are withdrawn tomaintain auto matically therein the quantity of stock at a uniformlevel, such as that indicated at 61 in Fig. 3. Fluid stock is fed fromtemporary storage tank 25 to the inlet end of the cylinder 29, which isclosed by head 34), by a suitable duct in any suitable manner at a pointpreferably below the level 61 dictated by float 60. Preferably, for thispurpose, a pipe 62 extends laterally to connect the interior of tank 25to an inlet opening 63 in the side of the inlet end of the cylinder 29,and preferably the top of that inlet opening and the top of the passageprovided by the interior of pipe 62 are located substantially at thelevel 61 which in turn is preferably in the vicinity of the axisof thecylinder, as indicated in Fig. 3. As a result, an appreciable gas headspace 64 is provided above the level 61 of the top of the fluid stock asit is supplied to the chamber 53 through the inlet opening 63.

Gaseous medium, such as carbon dioxide, nitrous oxide,

etc., but preferably air, is supplied directly to the gas head space 64in the cylinder chamber 53 at the inlet end.

For this purpose, a stand pipe 65 is preferably provided to communicatethe atmosphere with a gas inlet opening 66 in the top of the inlet endof the cylinder 29, as shown in Figs. 1, 3 and 4. This provides thenecessary gas requirements for producing the desired aerated conditionknown as overrun, fully discussed in my Patent No. 2,132,364 of October4, 1938. When pipe 65 is open to atmosphere for supply of air to attainthe desired degree of overrun, it may serve as a simple means wherebyfruit or other ingredients may be added in a ready manner by theoperator.

As shown in Figs. 1, 2 and 4, the outlet end of the freezer unit 23 isprovided with a suitably gated discharge passage which may comprise adepending tube 67 communicating with the chamber 53 by way of dischargeopening 68 and closed at its bottom end by pivoted gate 69 to be swunglaterally by a manual handle 70. Manual handle 70 is linked through abell crank lever 71 to a lift rod 72 pivotally connected to a foot pedal73, with the rod spring-biased downwardly by suitable spring means 74anchored to the rod in any suitable manner, such as by fixture 75.Fixture 75 may, if desired, be employed to operate a circuit closingswitch for energizing the freezer motor, as more fully explainedhereinafter in connection with Fig. 15. Thus, either by depressing footlever .73, or by swinging hand lever 70 to one side, gate 69 may becaused to uncover the outlet of discharge tube 67 for p delivery offrozen confection in a plastic condition for or feed it to the gatedoutlet fordelivery to customers.'

An embodiment of such dasher construction is shown in Figs. 3 to 9inclusive. As therein'indicated, such dasher construction may comprisea'rotary driving head 76 having a stepped cylindrical core element 77extending coaxially from a circular flange 78 provided with a pair ofdiametrically-arranged driving notches 79, 79. The driving head 76preferablyisprovided as an integral part of the driving shaft 80suitably rotatably supported in a journal 81 extending axially throughclosing head 30, with the shaft adapted to be driven by the pulleyconstruction 28. The smaller stepped portion of core element 77preferably constitutes'an axial extension 82 to be'slidably androtatably received in a collar 83 fixed on one end of a whipping bar 84.Preferably, the whipping bar 84 is rectangular in section and providedas a flat strip, although a variety of other shapesrrnightbe used; Theother closing head 31 carries a fixed, inwardly-extending stub shaft 85having a transverse slot 86 thereinto receive and hold the other end ofmixing or whipping'bar The agitating and advancing or feeding structureof the dasher construction may comprise a spiralled rod 90 having acomplete turn 91 at one end to be slidably received. over the largerportion of core 77 carried by driving head 76. vTurn'91 carriesdiametrically arranged, axially-extending driving lugs 92, 92 to bereceived in driving head notches 79, 79. The turnsofjthe 'spiralled rod90 are preferably of'an outside diameter slightly less than the internaldiameter of chamber 5350 as to be freely rotatable therein whileassuring obtainmentof maximum thrust. The other end of the spiralledwod90 has a turn 93 therein to receive the reduced portion of the rotatablesleeve 37 for support thereby.

In order to scrape the frosted material as it is formed on the insideface of chamber 53 therefrom and beat it back into the body of stockand/or forming plastic mate: rial, the spiralled rod 94) is providedwith a plurality of centrifugally-cockable, longitudinally-extendingscraper blades 94-94 so arranged that their sharpflleading edges overlaplongitudinally to scrape clean the entire inner surface of the freezingchamber opposed to the dasher construction. For support of each scraperblade 94, successive turns of the spiralled rod 98 are provided withopposed pairs of pivot pins 95, 95. Preferably each scraper blade 94 isof a shape similar to that shown in Figs. 4, 5 and 9, havingjasharpleading edge 96, an

longer front pivot pin and pushedtorward in the direction of the arrowto the dot-dashposition 147so ;that therear apertured car 109 may beslipped .oyerthe blades of the former pair.

cent portion of the turn of the :spiralled rod '90 *supporting it, asindicated in Fig. 4. Thus, as the dasher construction -is rota-ted :to.feed :the plastic v Imtterial forwvard through the cylinder chamber 153by ;screw; a c,tion,

the .action .of those scraper i-blades $94-94 {and drag of g material:thereon is prevented from ,dislodging or dis- :5

mounting the scraper blades, whilepermitting their ready removal ,for:conditioning and sharpening. Limited longitudinal motion of .eachscraper blade 94 -,in either direction is possible when thedasherz-frame ,and blades are disposed in and rotated in the Whippingchamber T 53,, but it .is limited -to :an extent preventing{disengagemenbofears 99 and "1G0 from;pivot pins ,95, 9.5.

A ,further simplified form of the .dasher construction which may bepreferred is illustrated in Figs. 1010 :14 inch, and, .as therein shown,may comprise a \pair of parallel, longitudinally-extending, Jaterallyspaced rods .101, .161 having their ends at theinlet end v,of,theapparatus fiattedat .102, 102,.as shownuin .Fig. 1l,,.-to .he suit-.ably received and .fitted in driving notches 19,,79. The .oppositeends1G3, 193 of the .rodsliil, 101 ,are adapted slid-ably .to be received indiametrically-opposed ,holes 104, 10.4 in the face of .fiange 18 8 of.amodified ,form of rotatable sleeve 87 to 'be mountedon stub shaft 85.The pair .of parallel rods .101, Mil "carry atspacedinterwith .those inone set 165-.- 1ti5,arranged obliquely ,forward with respect-totransverse planes, and alternateones of .the other .set 195-155 arranged,obliquely hackaway from such transverse planes, .as most clearly vSeenin :Fig.

.10. The blades 185-405 ,of onesetare locatedron one I.

sid of th pairofr d v 9.1, an tho e. of.. he other set ,1B5'-- 1G5' onthe opposite side, as will ,heseenpfrom Figs. 11 .and 12, so thattogether they fQEm v Screw structure adapted when rotated toadvanceplastic material from one end to the other.

Each blade 105 or 105' has an .outer edge 1%, substantially arcuate inshape and extendingahout1180i, to be rotated closely adjacent .to the.inner cylindrical surface of the chamber 53, as shown in Fig. 12.(Preferably the central portion at 107 of each .blade I05 or 105' is cutaway, as indicated in Figs. '11, 12 and 13, to provide clearance for awhipping or mixing member,

such as fixed bar '84. Thus each blade 105 or'1;05' may "be generally'C-shaped in outline, .with ,the tips thereof 'apertured at 108, .103,as indicated inFig, l3, slijdably toreceive the. rods 11,91,161, on"which the bladesvmay he thereafter fixed 'in proper positions in anysuitable .jmannerysuch as by welding, althoug'hother meanscarnied'thereby may be employed properly to space them.

It will be understood, however, that the centralportions of each blade106 need not be cut away at 1107 if the use ofa mixing or-whipping baris not desired,torreach blade may be somewhat fan-shaped and have amedial aperture in the area 107 to receive such a mixing or whippingbar.

Successive blades of 'each set 'obliqued in the same direction (105,105,01'105', 105') carry a pair of the opposed pivot pins (QS, 35 or 95)so that one of the scraper blades ,94, or .a scraper blade. of modifiedconstruction, may be mounted thereon in a manner similar to thatpreviously described. Thus, the "front end of a scraper blade mountedupon 'opposed pivot p ins'.95,

'95, on a pair of 'forwardly-obliqued blades 105, on one side of therods 101,161, will have its front end longitudinally overlapped by therear end of the next succeeding scraper blade pivotally mounted on theopposed pair of pivot pins 95', "95 of a pair of blades 't1'05',"105"'ob1iqued in the opposite direction to the rear "andwith 'the -rearblade of-that pair intervening the two Accordingly, the entire cylind iel rinn rsur ace of tt e chamber 55 ionn iteth adas e tcoustm tion illutra d :i liis 1 .;l4:i-nc usiii il bes ped e c ely by su b ade i r tatic'o the dasherqconstru'ction.

An efficient control system ior an embodiment of the apparatus of thepresent invention is diagrammaticalliy illustrated .in Fig. 15. ,Asitherein indicated, the valMe -48 may be of :the solenoid -type,.havingone end of an actuating magnetic .coil connected by wire ,109 to oneside TLZ of azs tpplycircuit at'110. Fhe other end'of the solenoid valveactuatingcoil is connected {by :a wire Mil 110 tthe movable mid ;pole1'12 iof;a1-si-ngle pole,-double throw switch 982, with ,one fixed:term-inal wthdledf marked A (automatic) connected" by wire {through afliermostat switch 114.to-the'other;side Ll' ofrthezsupply circuit at115. The 3freezermotorg38 zisiconneo'ted hy-wires 1-16 and 117-to-outputcterminals of'aidoubleipole, single ,throw relay -;:switch-=RS1,,- ySD that ithe Eblades thereof 11d 311d 1-19 may be :movedrespectively to conductive contact .with 'SUPP1Y1Gil'CUit' conductors1:1 :and

L2 so as to energize and operate 'rthe freezer m'otor.The-otheriterminal M ;(manual-) o'f swi-tch-.S2"-fis connected zbya wire12010 one output Itermi-nal of :the

--freezer motor relay switch fRS 1,".,'asshown, so that when that:switch :is .closed, :a circuit may be completed from oneside of the:supply circuit *Ll through zwire 1 20, .switch 32, wire111,:the=coil"of solenoid valve 48sand wire .109 to the :other side of:the supply :circuitWLZr Themelayswitch Rs l isprovided with :the usualclosing magnetic coil 121 which is connected betweenuone ;;side i-Ll=ofxthe supply circuit at 122 and -.a terminal123ofanothercontrol-switch S1 by wire 151.24. -Control-;switch *S11hasione terminal -M"(imanual') connected by =;wire "125 .toxthe otherside ELZ of :thesuppl-y"circuitxat.=126 so1that'1wi-th@c1osureiof switch.S1 o'n Ethe manual setting, relaycoil .121 -.will 'be' energized to:close relay switch RS1 .for running-=freezer"motor 38.

tcomp essor :motor 52 is connected :bywires 1 27 --arrd 12 8 to outputterminals of .a second irelay switch "RS2 .so- -that :when the movablecontacts 129 and d'30 thereof .are brought .to contact with terminalsconnected to supply circuit :lines Lil and EL-2; the compressor motorwill the energized and run.

Relay switch RSZ *is closable by :the usual magneticicoil 2131:connected between through a .-pr ssure responsive switch 134 10 theother side 12 of supply cirouit lineat 135. rcontrolwswitch ,S1.has itsother terminal .A (autornatic)riconneoted by a wire 136v toone outputterminalof the second relay switch RS2. so {that with switch ?S1-;onautomatic setting the coil 121 of the first relay switch RSFwill beenergized through the compressor motorrelayswitch 'RSZ only when thelatter is closed.

present invention comprises location of the control bulbs ,138 and 139along :the .return conduitSl in heat trans for association therewith,and-at locations substantially thermally remote from the i heattransfer-:spaceSO Jack'- et ng ,thetreezercharnber. It has b en foundthat :by

.such location of-such thermally responsive control :bulbs,

the temperature of the :frozen plastic material in the freezer can bemaintained more efiicientlvwithin a .nar-

row ,range ,of -;variation of ,temperature,;for example, see p errea'boubiof 24 F- In order-rte *as'sure such control response to thetemperature of ;the ;r, eturn conduit, h d o temp ratur infl en edefined by a suitable body of insulation .140 in whichthe two controlbulbs are embedded at 138 and 139. The temperature in that'field oftemperature influence preferably is furthrough heat transfer byconduction along the return conduit 51 from a point where it is exposedto contact with the atmosphere back to the points of location of thecontrol bulbs and, more particularly, to the location of control bulb #2at 138 which operates or controls the thermostat switch 114, the latteron automatic setting of the switches being responsive to open and closethe solenoid valve at 48. Thus, at least a section of the return conduit51 is made of heat conducting material, such as'copper or brass tubing,with a portion of that section being exposed to contact with theatmosphere and anothor portion thereof being embedded in the body ofinsulation 140 to lie adjacent the control bulbs at 138 and 139 for heattransfer to the latter.

In operation of the freezer apparatus shown in Figs. 1 to 9 inclusive,liquid confection stock contained in the elevated storage supply tank 54will be permitted to flow through duct 56 into temporary storage tank 55with valve 58 lifted by virtue of the'low position of float 66. As float60 rises with increase in the quantity of stock collected in tank 25,valve 58 will finally close the orifice in seat 57 with the surface ofthe liquid substantially at the level 61, Liquid stock will flow throughconduit 62 and inlet opening 63 into the inlet end of freezer chamber53, and with the body of the stock therein superposed by a head of airin space 64 in direct communication with the atmosphere through gasinlet opening 66 and gas supply stand pipe 65.

I The rotary dasher structure in the freezerchamber 53 will then berotated in a counter-clockwise direction as the dasher structure isviewed from the front or discharge end of the freezer, as indicated bythe arrow 141 in Fig. 8 and arrow 142 in Fig. 5. The dasher structure'isso rotated by means of shaft 8% drive pulleys 23 v and belted together,and freezer motor 38 which is suitably energized in one of a number ofpossible ways as hereinafter explained. The compressor motor 52 isenergized-suitably to operate compressor 41 so that pressure ofrefrigerant is built up in reservoir 43 to be supplied by supply conduitthrough the open solenoid valve 48 and the open expansion valve 49, andthence through duct 47 to the heat transfer space about the freezingchamber 53. With heat being withdrawn from the fluid stock in thefreezer as it is beaten and whipped,

frosted amounts thereof tend to build up on the inner wall of thefreezer cylinder 29. Rotation of the dasher structure causes the scraperblades 94-94 carried thereby to be swung outwardly or cocked bycentrifugal action so that their sharp noses or leading edges 9696 willscrape the frost from the wall of freezing chamber 53 to mix it backinto the body of supplied material and tobc churned up therein bycooperative action of the rotating spiral, the scraper blades, and theefiect of the fixed fiat mixing bar 84. As a result, partialsolidification of the confection stock will cause it to become ofplastic consistency and the resultant plastic body to be driven forwardby the rotating dasher structure to the discharge outlet 63.

The dot-dash line at 143 in Fig. 4 indicates the approximate surfaceshape of the supplied stock and partially frozen confection material asit is being frozen and agitated, and, as therein indicated, there is asubstantial gas head space 64 thereabove at the inlet end to permitsupplied gas or air to be whipped or beaten into the supplied stock asit is agitated in the freezer and chilled to freezing with attainment ofthe desired degree of overrun. The removal of the frost from the innersurface of the freezing chamber 53 by the series of scraper blades -9494is assured by virtue of the fact that longitudinally The frozenconfection in a plastic condition having the desired degree of overrunwill be withdrawn at will through the discharge outlet 68 and discharge67 by opening the gate 69 with lateral swing, either by swinging thehand lever 70 to one side or depressing the "foot pedal 7'3. Of course,at such times the freezer motor 38 must be operating the dasherstructure in order to cause the latter to fee'd the plastic materialforward by screw action. This can be accomplished in one of two ways;For example, if the movable contact 123 of switch S1 be moved over tothe' manual position to close the circuit at the fixed contact M, therelay coil 121 will be connected directly across the electrical supplyline to energize it and close switch RS1, which connects the freezermotor 38 to the'electrical supply line; Such energization ofthe freezermotor 38 may be effected automatically with opening of the dischargegate 69 by providing an automaticallyoperated circuit closing switch 145in shunt of the manual setting of switch S1 or, in other words,connected directly across between wires 124 and 125. Such a circuitclosing switch 145 can'be of 'a type wherein a biasingspring tendstomaintain it open with operating means opposing the force of thebiasing spring to close it. The operating means may be connected in anysuitable manner to any portion of the linkage connected between themanual lever 70 and the foot pedal 73, and for this purpose may, forexample,be connected to the biasing-spring anchorage fixed on therod.72.

' The modified form of dasher structure shown in Figs.

10 to 14 inclusive not only effectively accomplishes all 'of theoperational functioning of the embodiment shown in Figsx' l'to 9inclusive, but in addition, may be found to be much more readilyconstructed and manufactured in'rnass production. As will be'noted fromthe drawings, that second embodiment of the dasher structure isextremely simple and the parts thereof are readily and easily assembledto assure economy in production. Further, that structurepermits readymounting in the f freezer, allows efiicient agitating and screwadvancing op-- erations thereof, and also permits easy, quick and simplecleaning and servicing. Obviously, the scraper blades similar to'94which will be employed with the dasher structure shown in Figs. 10 to 14inclusive, are mounted and demounted in a similar simple manner. f Forexample, as shown in Fig. 9, in order to remove the scraper blade 94,one need merely to rotate it so that it extends s wardly or radial ofthe dasher structure proper,'and move it in the forward directionindicated by thearrow 146 to the dot-dash position 147, so as to freethe rear apertured car 100 from the rear pivoting pin to permit thefront apertured ear 99 to be slid back off of front pivot pin 95. Sucheasy removal permits sharpening of the scraper blade and anytruing up orother servicing thereof that may be necessary.

The control system of Fig. 15 will permit by proper setting of the twocontrol switches .S1 and S2, indicated on the front of the apparatus inFig. 2, to be manipulated to either manual operation or automaticoperation positions so as to control operation of the freezing apparatusin the following manners. For example, closure of switch S1 to themanual position by swinging its movable contact 123 over to the fixedcontact M will, as previously explained, connect the coil 121 of relayswitch fRSl across the electrical supply line"L1,L2" to close thatswitch and energize the freezer motor 38. Freezer motor cylinder toprepare frozen confectionhaving the desired overrun, and to drive itforward to the outlet'end ofithe freezer cylinder robe dischargedthrough the gated discharge opening at'the will of the operator tosupply a customer demand. The solenoid valve 48 which primarily controlscirculation of the refrigerant in the refrigerating duct system cannotbe turned on or, that. is, opened by energizationof its coil unless thefreezer motor is trunning awhen tswiteh ffS2 has it movable ,contact1112 also moved;overtfor circuit, closing :atlthe manualposition ,at"M.of-1course,-is-due toathe fact that while one :eudeofthesolenoidvalvecoil-is connected at 110 .to line "12, connection toline ,L1 is through the wfreezer imotor energizing relay switch-RS1,'.wire 120; and switch S2" when positioned :on manual setting.Thus, the freezer motor-maybe operated alone without;circulationof:refrigerant by closingcoil-circuit'of -RS1 eitherby -manual :settingof switch S1 or .by shunt switch 145 topera-ble-"bycthe gaterlink,"andithis, of course,:pennits delivery :from the rfreezer of :frozenplastic :confection product iby motor drive of the :dasher :structure,:while making it necessary.th-at the dasher structure :be rotated-by':the "ffreezermotor in order to obtain circulation of I rrefrigerantwhen switch :S2 is also at manual setting. This precaution, :of course,assures :that there can be no .-,such unduezbuild-up ofsolidified frozenmaterial on'the inner :walls :of-freezing chamber '53 as wouldypreventproper-operation ofthe device,'either by slowingor totally preventingrotation offthe agitating and feeding dasher structure.

Under such manual setting operation, and'with the 'thermostat switch"114 open, control bulb #1 at 139 ssolelyv-controls-the temperature.within thefreezer'since expansion valve 49 is controlled by thatcontrol bulb in response to return :duct temperature, and circulation ofrefrigerant as dictated by the opening of the expansion valve49.:Resposeto control-of the'bulbat'139 presumes that the solenoidvalveatAS is openby'energization of its 'coil withvs the control switchS2 on-manual settingand twiththefreezeramotor operating as a resultvofclosure ot-relay switch RS1 with control switch 'S1 also :on manualsetting. "The back pressure created in the re- *turn duct 51by'vaporization :of :refrigerant 'beyond the expansion valve 49-andthrough the freezer jacket chamber 50-'closes-the-pressure switchI34'toconnect the -coil'131 of rel-ay' switch RS2 by -wire 1 33 across thesupply circuit lines" L-'1 and L2 respectively between points 132 and1-35. "Thus, the compressor motor '5z-which is energized byclosureof-relay=switch RS2 -is;un'der the sole control 'of pressure' switch 134as itresponds to back pressure I in *the return duct-51 asconductedtherethrough -through duct 137.

latedto-automatic control-settings, such as by swing of movable ;contact123 of switch S1 to its 'tixedcontact 'A and swing ofthemovable'contact112- of switch" S2 to'itsfixe'cl contactA,''the circuits and-resultantoperations of the apparatusare as follows. Thecoil 1210f t relay switchRSl will'be connected across the electrical supplyline'betweenli1 at 122and"L2 through'con- ,tacts '12-3 andA of'Sl by Wire 136 only whenther'elay switch RS2 is closed, which, of course, is the wswitch.thatcsmnects ,the compressor motor across the snp 'ajlyline. Consequently,relay switch RS1 closes to pnergize andvoperatethe,freezer motor 38 onlywhen relay switch ,RSZKis closedto energizeaud operate the cornpressormotor 52. Relay switch RS2 is closedonly when the ,pressure switch 134is closed byback pressure created in the return duct 51 by vaporizationof the refrigerant. .Thus, only when refrigerant is circulating toproduce back pressure due to vaporization willithe compressormotoaSZ beenergized through ,re'lay switch fRSZ; ,and.since thefreezer motor 33.will runon auto- $10 htthegcontrol of l the (secondv controlcbulb .at1:138 Whit-211F830 resp0nds to-=elevatetl temperature above:armaximumqofta field of ,temperatureyinfiuen-ce 'of the ;return educt 5.3!38. point thermally remote from the freezeryjacket. Thus, thebtemperaturev'of the returmduct 5,1qcontrols 'theoperation,of,thethermostatswitch 114 whichrinzturn controlsthe'operation-of the solenoid valve '48, .zand:the latter will beopenedonly by-closure'of thezthermostatzswitch in-response to elevationof temperatureof'thezreturnrduct. However, this does not assurecirculation'of refrigerant since the expansionvalve must rbeaopenedbyits:control bulb at -139=also in response .toithe temperaturetofwthefield of temperature influence of .themeturnzduct. :The elevatedtemperature beyond a predetermined: maximum thus will cause expansionvalve 4910 be openedintresponse to the control bulb-at 139and'solenoid-valve zt8ttoabe opened by closure of theathermostatzxswitch .114:responding to the other controlbulb at 138. Theaconsequent circulation of refrigerant .in the "system :will:developiback pressure for closure'of'the'zpressure switch :l34-torcause--rela v.rswitch RS2;to close ifDIQCIlEIElZHllOH'Of thecompressonmotora-SZ, sand at. such -:tirne with-the: compressor motoroperating, the freezer motor will be=operated.

:Thus, t on automa tic:- setting, roperationt of J the thermostat switch;114-by its iCOIltTOiiblllb at tm6, in=response to the temperature :intthe afield .of z'ternperature influence 6f 52. eportiQu 10fFICil-Ill1.i.011dlllt:51, :dictates the opcration of t-theflow:ofirefrigerant'through theu'efrigerant circulatory ;;s yst em(:presuming-zthat ifrrthercontrol bulb l -at 1-39mm :used :it ris {alsorrespondiug :to r'that temperature to I open eexpeusion valve .49) ato:chill itl'le Wa'lls of #the freezing chamber-sandtdeveloptfrostthereon. 'With the thermostat gswiteh v it-lei "closed, the freezermotor {is -operated.to rotate :the ,idasher istructure in 'tthe freezerv chamber so as to scrape l the:;frost rfrom ithe lchall'lbfll walls,neat and whip :zit:back;into:tlieibodytofrsupplied stock to-form afrozen ,plasti'c produchsalso :to heat into the supplied stoc'k su'f-:ficieut quantity of sgas orair to attain -the-desired overturn, :and:also rto 'feed sthe finished :plastieproduct forward :to {theoutlet-iend :and through the gated'ou'tlet when totteired sforsupplyroftcustomer demands. 'Thus, Wit-h ithercontrol sWitchesflSland*S2 manipulated to auto- :matic zsettin'gs, thetherm'ostab switch"114 'and its control bulb #2 eat r138-may he considered to be "themaster rcontrol devicerot'tth-e controlsystem.

JAISQ, ithough not i entirely necessary, it is desirable "to use acontrol bulb for dictating=thesetting-of the expan- -sion:valvei49,tsuchas that at 139, soithat there will be rtemperature rcontrol of the tlow"of refrigerant through :the :refrigerant :circulatory i-system at alldimes. As --.:explained, 'lWh8l1V6I"COIltI'Ol switch S2 is on manualzsetting-zsolenoid valve 184s openedmpon'o-peration of the lflIEZYm0l0r38 -throu'gh closure of "the relay switch R-S12" But, of course,rotation of v the .dasher. structure by-the fre cz-er motor 33 is*frequen'tly desired whenlthere "is no tiemandfon heat transfer from theconfection, materialinthefreezerysuch as at times ofdevelopingoverrunand deliveringfinished,productfrom thefreezer. Under such conditions.when there ,is x no refrigerant flow :control by control bulb '.#2,control bulb -#-1 at v1'39 :performs that ,function. 0n zautomaticsetting :of @control :switch fS2 ,-,of;course,the-solenoid valve 48 isconnected across the supply line only through closure of the thermostatswitch 51:14 operated by its "controlbulb'#2.at.;138,' which,

'- in;:turn, nfespondsxto tthe'ttemperature of the held of influ-:"EIICB 10f sthe-rretuitn :iconduit rtemperature. Thus, the use of:thettwo:controlbulbs -'#.1 sand #2 assures that circulaztion:oftrefrigerant in its :circulatory .system is permitted only when thetemperature of the field oftemperature iinfluence :ofthe rreturn conduitbecomes higher than a 'tpredetermined martimumso as demand-front one ormore of the control 'bulbs operation "of equipment whi'ehwwill :permitsuch flow. Accordingly, no combination of manipulations of the twocontrol switches "3915 and *SL? 11 is possible by an unskilled operatorwhich will cause improper operation and possible development ofsufficiently solid frozen material in the freezer as to retard unduly orprevent rotation of the dasher structure.

It will thus be seen that the objects set forth above, among those madeapparent from the preceding description are efficiently attained and,since certain changes may be made in the above construction anddifferent embodiments of the invention could be made without departingfrom the scope thereof, it is intended that all matter contained in theabove description or shown in the accompanying drawings shall beinterpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended tocover all of the generic and specific features of the invention hereindescribed. and all statements of the scope of the invention which, as amatter of language, might be said to fall therebetween.

Having described my invention, what I claim as new and desire to secureby Letters Patent is:

,1. In apparatus for producing frozen confections the combination with afreezer having a motor for operating a dasher thereof; and a refrigerantcirculatory system therefor including heat exchanger means and acompressor having a motor, a solenoid valve and an adjustable expansionvalve in series in a high pressure conduit means between said compressorand said freezer with each of said valves adapted to control flow ofrefrigerant in said system, and a low pressure return conduit meansbetween said freezer and said compressor; of heat-responsive means toadjust said expansion valve located in a field of influence of thetemperature of said return conduit means substantially theremally remotefrom the freezer proper and its heat exchange means; an electricalsupply circuit for said freezer and compressor motors; and means tooperate said solenoid valve including thermostat switch meanselectrically to connect it to said electrical supply circuit, andheat-responsive means to operate said thermostat switch means alsolocated in said temperature field of said return conduit meanssubstantially thermally remote from the freezer proper and its heatexchange means; said pair of heat-responsive means being adaptedrespectively to open said expansion valve and close said thermostatswitch means for simultaneous opening of both of said valves at apredetermined elevated temperature of said return conduit meanstemperature field as distinguished from said freezer proper.

2. The freezing system as defined in claim 1 characterized by relayswitch means to connect said compressor motor to said electrical supplycircuit, pressure-responsive switch means to close said relay switchmeans, means to apply back pressure in said return conduit means to saidpressure-responsive switch means to close the latter, other relay switchmeans to connect said freezer motor to said electrical supply circuit,and means to energize said freezer motor relay switch for closurethereof connected to said electrical supply circuit through saidcompressor motor relay switch.

3. The freezing system as defined in claim 2 characterized by switchmeans selectively to connect said freezer motor relay switch energizingmeans directly across said electrical supply circuit and simultaneouslyto break the circuit connection through said compressor motor relayswitch means.

4. The freezing system as defined in claim 3 characterized by additionalswitch means selectively to connect said solenoid valve across saidelectrical supply circuit through said freezer motor relay switch meansand simultaneously to break the circuit connection through saidthermostat switch means.

5. In apparatus for producing frozen confections the combination withfreezer structure including a freezer proper and a refrigerantcirculatory system therefor including a heat exchanger in said freezerproper, a high pressure supply conduit means leading to the latter and alow pressure return conduit means leading from said heat exchanger; ofheat-responsive means located in a field of influence of the temperatureof said return line substantially thermally remote from the freezerproper and its heat exchanger, and a pair of valve means in said highpressure supply conduit means controlled by said heat-responsive meansto be opened for circulation of refrigerant when the temperature of saidfield reaches a critical maximum; one of said valve means comprisingsolenoid valve means having an energizing electrical circuit includingthermostat switch means operable by said heat-responsive means, theother of said valve means being an expansion valve also controlled bysaid heat-rcsponsive means located in said field.

5. The freezing system as defined in claim 5 characterized by insulatingmeans covering a portion of said return conduit means to define saidtemperature field, said heatresponsive means for said pair of valvemeans being covered by said insulating means in heat transfer rela tionto said return conduit means substantially thermally remote from saidfreezer heat exchanger.

7. The freezing system as defined in claim 6 characterized by saidreturn conduit means having a section formed of heat conducting materialwith said insulating means covering one part of said section whileanother part thereof is exposed in heat exchange relation to thesurrounding atmosphere for tempering the temperature in said field.

8. In apparatus for producing frozen confections the combinationcomprising a freezer having a motor for operating dasher feeding meansthereof; a refrigerant circulatory system including a heat exchanger insaid freezer, a compressor and storage unit having an operating motor, ahigh pressure supply conduit leading from the latter unit to said heatexchanger, and a low pressure return conduit leading from the latter tosaid unit; a solenoid valve and an adjustable expansion valve in seriesin said high pressure conduit with each adapted to control flow ofrefrigerant in said system with said solenoid valve having an operatingcoil to open it when energized; an electrical supply circuit for saidfreezer and compressor motors; a pair of relay switches each having aclosing coil and respectively adapted to connect said motors to saidcircuit; a thermostat switch having heat responsive means to close it atelevated temperatures with said means located in heat transfer relationwith respect to a heat-conductive section of said return conduit;insulatingmeans housing a portion of said section to define a field oftemperature influence thermally remote from said freezer heat exchangerwith said heat responsive means located therein for protective isolationfrom the surrounding atmosphere, another portion of said section beingexposed to the surrounding atmosphere for conductive tempering of thetemperature of said field; other heat-responsive means also located insaid field operating said expansion valve to permit fiow therethrough atelevated temperature; a double throw switch alternately to connect saidsolenoid valve coil to said supply circuit through the freezer motorrelay switch when closed and through said thermostat switch; apressure-operated switch connected to said return conduit to be closedby refrigerant back pressure therein adapted to connect said compressormotor relay switch coil across said supply circuit to close the latterswitch; and a second double throw switch alternately to connect saidfreezer motor relay switch coil to said supply circuit directlythereacross and through said compressor motor relay switch when thelatter is closed. 7

References Cited in the file of this patent UNITED STATES PATENTS2,064,131 Tuscan Dec. 15, 1936 2,077,865 Wile Apr. 20, 1937 2,163,995Fuller June 27, 1939 (Other references on following page) 13 Vogel Dec.5, 1939 Kaltenbach June 30, 1940 Johnson Aug. 6, 1940 Shaw Nov. 12, 1940Holmen Dec. 8, 1942 5 Johnson Sept. 7, 1943 Smith Jan. 4, 1944 14Wiegers Sept. 18, 1945 Kolz July 27, 1948 Stickel Jan. 9, 1951 TachellaJuly 3, 1951. McGrath Dec. 11, 1951 Erickson Feb. 26, 1952

